PERCEPTION OF SWEETNESS AND BITTERNESS IN DIFFERENT VEHICLES

In the present study, we investigated taste-taste, taste-vehicle, and simultaneous taste-vehicle-taste mixtures. Subjects made estimates of the sweetness and bitterness of 27 stimuli. Sucrose (292, 585, and 117 0 mM), caffeine (13, 26, and 52 mM), and binary mixtures of low (292-1 3 mM), middle (585-26 mM), and high (1170-52 mM) levels of both compon ents were dispersed in water, carboxymethylcellulose (CMC) 1% w/v, and gelatin 6% w/v. The sweetness and bitterness of the sucrose-vehicle-c affeine combinations were significantly weaker than the respective suc rose-vehicle and caffeine-vehicle combinations. The emerged mutual sup pressive effects were asymmetrical and persisted when both tastants we re presented in CMC and gelatin. Moreover, the increase in vehicle con sistency and the simultaneous addition of another taste reduced the pe rceived intensity of a taste either presented alone or dissolved in wa ter. For both sweetness and bitterness, the total taste suppression ob served was always significant.